DAMQT: A package for the analysis of electron density in molecules

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• 作者：Rafael Ló ; pez ; Jaime Ferná ; ndez Rico ; Guillermo Ramí ; rez ; Ignacio Ema ; David Zorrilla
• 关键词：Electron density ; Electrostatic potential ; Electric field ; Hellmann– ; Feynman forces ; Density deformations
• 刊名：Computer Physics Communications
• 出版年：2009
• 出版时间：September 2009
• 年：2009
• 卷：180
• 期：9
• 页码：1654-1660
• 全文大小：504 K

文摘

DAMQT is a package for the analysis of the electron density in molecules and the fast computation of the density, density deformations, electrostatic potential and field, and Hellmann–Feynman forces. The method is based on the partition of the electron density into atomic fragments by means of a least deformation criterion. Each atomic fragment of the density is expanded in regular spherical harmonics times radial factors, which are piecewise represented in terms of analytical functions. This representation is used for the fast evaluation of the electrostatic potential and field generated by the electron density and nuclei, as well as for the computation of the Hellmann–Feynman forces on the nuclei. An analysis of the atomic and molecular deformations of the density can be also carried out, yielding a picture that connects with several concepts of the empirical structural chemistry.

Program summary

Program title: DAMQT1.0

Catalogue identifier: AEDL_v1_0

Program summary URL: http://cpc.cs.qub.ac.uk/summaries/AEDL_v1_0.html

Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland

Licensing provisions: GPLv3

No. of lines in distributed program, including test data, etc.: 278 356

No. of bytes in distributed program, including test data, etc.: 31 065 317

Distribution format: tar.gz

Programming language: Fortran90 and C++

Computer: Any

Operating system: Linux, Windows (Xp, Vista)

RAM: 190 Mbytes

Classification: 16.1

External routines: Trolltech's Qt (4.3 or higher) (http://www.qtsoftware.com/products), OpenGL (1.1 or higher) (http://www.opengl.org/), GLUT 3.7 (http://www.opengl.org/resources/libraries/glut/).

Nature of problem: Analysis of the molecular electron density and density deformations, including fast evaluation of electrostatic potential, electric field and Hellmann–Feynman forces on nuclei.

Solution method: The method of Deformed Atoms in Molecules, reported elsewhere [1], is used for partitioning the molecular electron density into atomic fragments, which are further expanded in spherical harmonics times radial factors. The partition is used for defining molecular density deformations and for the fast calculation of several properties associated to density.

Restrictions: The current version is limited to 120 atoms, 2000 contracted functions, and l_max=5 in basis functions. Density must come from a LCAO calculation (any level) with spherical (not Cartesian) Gaussian functions.

Unusual features: The program contains an OPEN statement to binary files (stream) in file GOPENMOL.F90. This statement has not a standard syntax in Fortran 90. Two possibilities are considered in conditional compilation: Intel's ifort and Fortran2003 standard. This latter is applied to compilers other than ifort (gfortran uses this one, for instance).

Additional comments: The distribution file for this program is over 30 Mbytes and therefore is not delivered directly when download or e-mail is requested. Instead a html file giving details of how the program can be obtained is sent.

Running time: Largely dependent on the system size and the module run (from fractions of a second to hours).

References: [1] J. Fernández Rico, R. López, I. Ema, G. Ramírez, J. Mol. Struct. (Theochem) 727 (2005) 115.